bug: RayDistributedStrategy doesn't propagate ingest errors correctly

[micpst]

What happened?

Currently ingest steps return IngestDocumentResult which contains an error field that can store any exception from the task. Most of these exceptions can't be serialized properly, resulting in error during ingest and messing up the entire pipeline.

The solution would be to change the error field in IngestDocumentResult to store only the error type and add fields for error message and stack trace.